Change mesh to to GameObject

Hi guys! I'm using a script to place objects on a grid that I found made by the community (thank you!) and it has a mesh that is drawn purple on the grid where the mouse is positioned. Now I want the mesh to instead of being just a solid color I want it to be a GameObject. How would I modify this code to make it a GameObject instead?

     private Mesh mesh;
      
     private Vector3[] verts;
     private Vector2[] uvs;
     private int[] tris;
      
      
     void ConstructMesh()
     {
         if ( !mesh )
         {
                mesh = new Mesh();
             MeshFilter f = GetComponent("MeshFilter") as MeshFilter;
             f.mesh = mesh;
             mesh.name = gameObject.name + "Mesh";
         }
      
         mesh.Clear();  
      
         verts = new Vector3[9 * 9]; 
         uvs = new Vector2[9 * 9];
         tris = new int[ 8 * 2 * 8 * 3];
      
         float uvStep = 1.0f / 8.0f;
      
         int index = 0;
         int triIndex = 0;
      
         for ( int z = 0; z < 9; z ++ )
         {
            for ( int x = 0; x < 9; x ++ )
            {
              verts[ index ] = new Vector3( x, 0, z );
              uvs[ index ] = new Vector2( ((float)x) * uvStep, ((float)z) * uvStep );
      
              if ( x < 8 && z < 8 )
              {
               tris[ triIndex + 0 ] = index + 0;
               tris[ triIndex + 1 ] = index + 9;
               tris[ triIndex + 2 ] = index + 1;
      
               tris[ triIndex + 3 ] = index + 1;
               tris[ triIndex + 4 ] = index + 9;
               tris[ triIndex + 5 ] = index + 10;
      
               triIndex += 6;
              }
      
              index ++;
            }
         }
      
      
         // - Build Mesh -
         mesh.vertices = verts; 
         mesh.uv = uvs;
         mesh.triangles = tris;
      
         mesh.RecalculateBounds();  
         mesh.RecalculateNormals();
     }
      
      
     void UpdateMesh()
     {
         int index = 0;
      
         for ( int z = 0; z < 9; z ++ )
         {
            for ( int x = 0; x < 9; x ++ )
            {
              verts[ index ] = mapGrid[ x, z ];
      
              index ++;
                 
            }
         }
      
         // assign to mesh
         mesh.vertices = verts;
      
         mesh.RecalculateBounds();
         mesh.RecalculateNormals();

Thanks!